Process for producing homogeneous metalliform carbonitrides and for superficial nitrification of tungsten



Patented Apr. 28, 1931' UNITED. STATES PATENT OFFICE Brennan 3.. IWAIIHVEB, F NUREKBERG, GERMANY PROCESS FOR PRODUCING- EOIOGENEOUS METALLIFOBM CARBONITBIDES AND FOR SUPEBI'IOIAL NITRIFICATION OF TUNGSTEN" Io Application filed March 6, 1928, Serial No. 259,605, and in Germany May 18, 1927.

The combinations of nitrogen with metals, so far as they disclose metallic character, reveal themselves throughout as of great hardness. Heretofore, in t e case of articles sub- 'ject to hard wear this characteristic has been 19 stances and exactly specified conditions andand the dc cient react1on or reactionability utilized by su rficial nitrification and thereby supplied t em with a hard outer la er.

Such earlier nitrification is success 111 in useful form only under very definite circummoreover was previously not possible with a considerable number oi metals. For instance, the nitrification of'metals of the chromium grou has not as yet been accomplished between nitrogen and, for example, tungsten has been utilized in such a way that, during the later working with tungsten in highly heated condition, it was envelo with. a nitrogen atmosphere as a protection against oxidation. f

I'have made the discovery that the nitrification is consummated with markedly greater facility and is also possible with such metals which heretofore resisted it, especially with all metals of the iron and chromium groups, when the nitrification proceeding follows a superficial carburization or when a carburization occurs simultaneously with the nitrification. 0

For example, iftun en, which heretofore I has not been capable o nitrification in the ordinary way is shortly beforehand superficially carbonized, either while glowing m pulveri'zed carbon or through transition of h drocarbons and then ex osed to the action o the nitrogen, the nitri cation eventuates in a satisfactor manner in a short time. The utilization of disassociated nitrogen thereby proves itself as particularly advantageous, for example, by aggregation with known nitrocompounds like the cyanamids and carids among others; "or by transition of gaseous or vaporous'nitrogen compounds.

According to my declared invention the carburization process can also occur simultaneously with the nitrification; in addition to the use of tenacious combinations the gas like reaction medium here shows or vaporitself advantage. Thus, for example, am-

. metals and substitution may also be made for themby vaporous, fluid hydrocarbons like benzol vapor.

With the aid of the foregoing method it is also possible to nitrificate without diificulty metal carbides which heretofore likewise resisted reaction with nitrogen, as for example the carbides of chromium or tungsten or molybdenum and others, advantageously also in apowdel'ed'condition.

According to this process, heretofore unknown nitrogen compounds with carbon and heavy metals occur, 'which I term carbo nitrides. v

The process is according to my invention successful only if,as described, disassociated or nascent nitrogen is utilized.

I claim 1. The process bonitrides, comprising, causing carburization'and nitrification reactions with tungsten to occur in the presence of carbon, dissociated nitro en and heat. w

carbonitride which comprises, exposing a pgwdered mass of tungsten and a. hydrocarn to dissociated nitrogen in the presence of heat.

5'). The process for producing homogeneously permeated tungsten carbonitride articles which comprises, bringing tungsten carbide to a glowing heat while exposing to the action of dissociated nitrogen.

4. The rocess for achieving a tungsten carbonitri e, which comprises, exposing a powdered mixture of carbon and tungsten 0 dissociated nitrogen in the presence of cat.

5. The process for producing metalliform tungsten carbonitride, comprising, bringing he process for producing a tungsten so i a powdered tungsten aggregate to a glowing heat in the presence of a car onaceous vehicle and subjecting the carburized tungsten pow-' der to dissociated nitrogen while maintaining the heat, whereupon a 'carbomtrlfication reaction occurs homogeneously throughout the aggregate.

'6. The process forproducing tungsten carg 7o 7 for producing tungsten car'- 1 RICHARD R. WALTER.

Minimum$1M 

